Every time I float a window from the editor, or even the Blender main window, and try to resize it, placing the mouse in the corner (it shows the icon to horizontal or vertical resizing), the moment I click, the window is deselected and jumps to back to the main window. Anyone had this same problem? Any clue how to solve it?

I realized what's happening. It's a user interface problem by Blender in Mac OSX. When u pointing the mouse at the lower right corner it shows the horizontal or vertical symbol to resize that window, but it not works. When u click it changes the window focus. Otherwise u have to point the mouse at the lower right corner, but not in the extremely edge, where the mouse havent changed yet to those resizables symbols, and drag the window to modify it dimension.